Leucine modifications by He/O2 plasma treatment in phosphate-buffered saline: Bactericidal effects and chemical characterization

0555846 - ÚFP 2022 RIV GB eng J - Journal Article
Jirásek, Vít - Koval'ová, Zuzana - Tarabová, Barbora - Lukeš, Petr
Leucine modifications by He/O2 plasma treatment in phosphate-buffered saline: Bactericidal effects and chemical characterization.
Journal of Physics D-Applied Physics. Roč. 54, č. 50 (2021), č. článku 505206. ISSN 0022-3727. E-ISSN 1361-6463
R&D Projects: GA ČR(CZ) GA19-25026S
Institutional support: RVO:61389021
Keywords : amino acid * atmospheric-pressure plasma jet * bacteria * hypochlorite * leucine * oxygen atom
OECD category: Fluids and plasma physics (including surface physics)
Impact factor: 3.409, year: 2021
Method of publishing: Limited access
https://iopscience.iop.org/article/10.1088/1361-6463/ac252e

We studied the chemical and bactericidal properties of plasma-modified amino acid leucine (Leu) treated in phosphate-buffered saline (PBS) using an atmospheric-pressure plasma jet operating with He/O2 gas. We determined the initial formation of hypochlorite by the reaction of plasma-supplied O atoms with chloride ions in PBS, followed by the subsequent chlorination of Leu. The principal chemical process involved the formation of Leu monochloramine and Leu dichloramine. The products of plasma-modified Leu further possessed post-discharge reactivity characterized by the decay of Leu chloramines to the secondary products, i.e. isovaleraldehyde, isovaleronitrile, and N-chloromethyl-3-butaldimine. Our study of the effects of Leu on the viability of Escherichia coli bacteria in the plasma-treated PBS solution demonstrated time-and pH-dependent cytotoxic behavior, which were associated with the formation of different reaction products. At shorter treatment times, the addition of Leu hindered the bactericidal properties of plasma-treated PBS caused by the consumption of bactericidal hypochlorite in reaction with Leu and formation of non-bactericidal Leu monochloramine. Acidification to pH = 3 and longer plasma treatment substantially enhanced the bactericidal effects of Leu solutions, which were tentatively assigned to the formation of Leu dichloramine.
Permanent Link: http://hdl.handle.net/11104/0330303